RAID Data Recovery – How It Works

May 13, 2018

RAID data recovery is probably one of the most complex processes any data recovery firm can perform. More often than not, the problems are compounded by the actions of the client prior to sending the drives in for recovery. Many users feel that it is important to try and recover the data themselves or repair the array through various system utilities, and this may be fine if the data is not critical. However, it has been our experience that when you have a RAID failure that has resolved in substantial data loss, more often than not, somebody's job is on the line if that data is not recovered. The largest piece of advise this article can provide in the event of a RAID failure: LEAVE IT ALONE.

IT professionals have a lot of pressure placed on them when a catastrophic system failure occurs. It is their job to make sure that all systems are up and running. Many times, out of panic, troubleshooting processes are initiated in order to correct the problem. Often times these processes only make a bad situation even worse, and in many instances they can render the data unrecoverable. Let's keep in mind what this data can consist of in an average corporate environment. You are probably dealing with information that cost many hundreds of thousands of dollars in labor and resources to create. Much of the data probably can not be duplicated. The intellectual value alone could have been in the many millions of dollars. Corporate executives really do not care to hear about how the failure occurred, or what unbelievable string of events led up to the server crashing. They do not care to hear the technical jargon as you try to explain to them what happened, and hope they understand that it was not your fault. They only want to know one thing … "Why was this data not backed up, and how can we get it back?"

Instead of taking chances on your own, call a data recovery professional. RAID data recovery can be expensive, but in most cases it is much less costly than trying to recreate the data that has been lost. There is a set procedure that most data recovery professionals follow when it comes to performing any recovery work. These procedures are followed and expanded upon when dealing with a RAID recovery. The first step of any RAID recovery is to make sure all of the drives are functional. In order to properly complete the recovery it is essential that all drives are fully functional (this is especially true with a RAID 0). This may involve taking any physically damaged drives into the clean room, in order to make the necessary repairs so that they function normally again. Once that is completed the next step is to make complete, sector-by-sector clones of every drive. This is not "Ghosting", but a very low-level process that allows the recovery technician to work around bad sectors, and have complete control over how the drive functions. During the cloning process, the original source drive that you sent in, is generally put in a "write protect" mode so that no data can be written to the drive. This insures that the original source data is not altered in any way.

Once the cloning process is complete, the original drives you sent in are set off to the side and are no longer touched. The actual recovery process is performed on the cloned copies, so nothing that is done during recovery can make the situation worse. After the drives are cloned, they will be loaded into an emmulator and destriped. Destriping is like taking the scattered pieces of a puzzle and putting them together neatly. Simply stated, destriping is taking the data scattered among the multiple drives that make up array and placing it onto a single destination drive. From there we have a single drive in which we can complete what we would consider to be a "normal" recovery. We can complete this process even at the multi-terrabyte level. If the damage to the stripe is not too severe, in most cases a complete rebuild of the directory structure and all associated data can be completed.

As mentioned earlier, RAID data recovery can be expensive. Depending on the company you contact the prices can vary considerably. Typically a RAID recovery can be priced anywhere from $ 800 to $ 3,000 per drive. A number of factors influence the cost, such as RAID type, file system, total size, situation of failure, etc. Many times attempt fees and assessment fees are charged if the data is unrecoverable. This is understandable due to the amount of time and resources required to perform a single RAID recovery. However, in most cases the costs involved in recovering the data are not even 1% of the data's overall value. If you are reading this article and you have not suffered a RAID failure, what are you waiting for? Back up your data NOW.

37 Comments

I had this problem and had EE in my hex code so I tried this software and it worked. Once you are in the software on the left is a "partition recovery wizard" works like a champ. I hate software that is "free to try with limited functionality" but hey, it was just enough…

Thank you! I pulled a HD out of an old XP computer and was getting the invalid disk problem when I was trying to read it on a new Win 10 PC using an external enclosure. This trick made the disk work and allowed me to get my old files. Thanks again!

Hi, I followed your instruction, but I have gotten into a new problem. I had 4 partitions, after this i can see only 3 partitions, the previous system drive and two other drives which are not accessible. everytime i try to click on those two, i am asked to format the drives. Please help

Thank's alot asshole. Your 'excellent' instructions in which you state to open Hard Disk 2 made me fuck up my system. System won't recognize my ssd anymore. Don't follow this tutorial if you want to save yourself some pain!

Hi, I can only get 2 drives. Another drives shown as D:/ not accessible Parameter Incorrect. As u said I have partitions and I changed all from 42 to 07. I converted my another Laptop HDD and connected to another Laptop.

I have changed the hard disks of my computer. I made the previous hard disk an external hard drive by using an external HDD cas. I want to copy a folder from a particular partition from the drive to my new drive. But after connecting the drive to the system I am unable to see it in My comuter. In disk Management it shows as 'Dynamic Invalid Disk'. After watching your tutorial I tried to follow the steps you mentioned, but was unable to see 42 or 07 in any of the Partition you mentioned in the Hard Disk 2. I can only see 0 in all the columns.Kindly help.

IF YOU HAVE EE OR EF IN HEX OR IF YOU GOT this operation is not allowed on invalid disk packCHILL OUT!just use MiniTool Partition Wizard choose convert dynamic disk to basic it will work for you and 3 seconds you will see all your partitions!

IT WILL WORK EVEN THE WINDOWS DISK MANAGMENT DIDN'T WANT TO CONVERT IT